Help with this bathroom faucet

New to forum and thanks in advance for any help. My problem is when I changed counter top on vanity to granite all went great untill I put my faucet in and tightened the plastic big threading piece to underneath the counter. After I did that there were no threads sticking out to hook my water lines to, the thread was flush with the bottom of the fastener. What can I do/do they make something you can attach?